Support for drill pipe protectors



@ci 2l E947 J. c. BALLAGH SUPPORT FOR DRILL PIPE PROTECTORS Filed April 1'7,y 1944 @wir 10 W A m l [Il Aw M M z J wf `I Patented oci. 21, 1941 surrolrr Foa pmu. PIPE Pao'rnc'rons James c. nauagh, Los Angeles, cam.,'m|gnor, by

mesne assignments, to Byron Jackson Co., Vernon, Calif., a corporation of Delaware Appuuqn april 11. 1944, serial No. 531,349 2 claims. (c1. '2s- 236) I'his invention relates to an expander for drill pipe protector, In the art of drilling oil wells by the rotary method, a drill pipe is used to transmit power to the bit at the end of the drill pipe. The drill pipe operates inside of a casing known asa well casing. In orderto prevent the drill pipe from rubbing and wearing against the casing, it is common practice to place upon the drill pipe a heavy rubber sleeve known as a protector. Ihese protectors are in the form of'a seamless rubber ring, the internal diameter of which, before installation on the drill pipe, is considerably less than the outer diameter of the drill pipe on which the protector is to'be installed. The elastic properties of the protector when expanded and stretched to position on the drill pipe are relied upon for holding the protector in position. In

vorder to install these protectors upon the drill pipe, itis necessary that they be expanded not only sufficiently to pass over the drill pipe, but alsov sufficiently topass over the tool joint on the end4 of the drill pipe. For this purpose devices known as expanders are employed and very heavy loadsare placed on these expanders.

The expanders now commonly employed in the art are subject to numerous defects in'that parts of the expanders may become bent so. that the expanders do not properly function. The general object of the presentinvention is to provide an expander of an improved type which will better withstand the loads encountered in expanding the protectors and which is not readily subject to being bent in operation.

In the expanders commonly employed for in stalling protectors on drill pipes, there is employed a center shaft which serves as a 'guide for the drill pipe and mandrel ofthe expander while the drill pipe is being lowered relative to the expander. These center shafts have heretofore been xed .to the base of the expander with the result that where the drill pipe is held at a slight tilt relative to the expander the center shaft frequently becomes bent. To obviate these diilculties in the present invention the expander is provided with a hollow cylindrical extension of the base and the center shaft is iixed to a disc which loosely rests at they bottom of the base extension, the disc having a very loose t with the cylindrical base so as to permit tilting of the drill pipe and center shaft with reference. to the base of the protector without bending the center shaft.

A further defect of the expanders commonly used resides in the ease with which the customary spring arms are bent in operation. In order to overcome these difficulties inthe expander of the present invention, the arms which support the l protector, contacting pads ordogs, are rigidly constructed and possess no appreciable spring ac- 5 tion. These rigid arms are pivoted to the vbase at one end and at their other end have a slight pivoting connection with the pads or dogs which are intended to contact the protectors. A further improvement in the expander ofthe present invention resides in the form of the pads or dogsr employed in contacting the protectors. These pads or dogs are provided with lips on their upper interior faces which are intended to be wedged in the bore of the protectors, facilitating l5 the expansion of the protectors.

The expander of the present invention, Atogether with various other advantageous features of the same, will be fully understood from a description of a preferred form or example of an 20 expander embodying the invention.

tion of the operation.

at 2 the lower end of the tool joint of the drill prises a base member 9 which is in the form Figure 3 is a plan view of the dog or pad.

Figure 4 is a fragmentary vertical section mainly through one of the armsof the device.

Referring to the drawings, I have indicated pipe over which a protector is to be expanded. For this purpose the protector 3 is mounted upon a. cone I which has a reduced lower sleeve 5 upon which the protector is to be mounted before 4the expanding operation. The cone is provided with an expanding portion 6, the end' of which is adapted to engage the shoulder 8 of the tool joint 2.

The expander of the present invention comof a ring having a depending cylindrical flange I0. The depending flange l0 is fixed to a hollow cylindrical member Ii which forms an exten.

5o sion of the base. The cylinder Il in turn is The center shaft I4 is thus capable of tilting with- 'On the base I there is provided bifurcated earsz Il which support pins l1 pivotally mounting arms Il. Four of the arms il are shown, although various numbers of arms may be em-` ployed. These arms have squared lower ends Il shaped to engage the members I6 tolimit the outer pivoting of the arms to substantially theupright position as exhibited in Figure 2, vthe inner lower faces of the arms being curved to permit the arms to swing inwardly, as desired.

The upper ends of the arms extend into pockets in the lower ends of dogs or pads 2|. These pockets ilt the upper ends of the arms i8 loosely in order that the dogs may be provided with a slight pivotal or universal movement with respect to the upper end of the arms. Set-screws 22 pass through the dogs 2| and into the arms I8 for holding the dogs to the arms. 'I'he openings 4for the set-screws 22 in the dogs 2| Vare drilled somewhat larger than the set-screws so as not to interfere with the slight intended universal movements of the dogs with respect tolthe arms.

The upper faces of the dogs 2| are substan-f tially fiat, except at the Vinterior of the dogs, where there are provided upwardly curvingy lips 23 which are intended to wedge within the bore of the protector 3 at the start of the expanding operation.

The side walls of the dogs 2| extend radially for a distance and each dog 23 is-provided with one side having a locking shoulder 23a adapted to engage a complementary recess 23h on the adjacent dog. These shoulders provide a frictional lock to prevent radial movement of the dogs when the dogs are in the position indicated in Figure 3, and are of great assistance in holding the apparatus in intended position previous to the expanding operation and assist in setting up the apparatus in position for operation.

In the operation of the expander of the present invention. the expander is normally placed in suitable position in the well derrick, such as on the drilling table at one side of the opening thereof. The rubber protector sleeve 3 is then placed on the cone 4 in the position indicated in Figure 1, and the cone placed over the center shaft |4 until the protector 3 engages the lips 2l of the dogs 2l as indicated in Figure l. 'I'he drill pipe on which the protector is to be positioned is then lowered down the derrick until contact is made between the shoulder of the joint of the drill pipe and cone. Subsequent lowering of the drill pipe then forces the protector I to move up the cone. to be expanded and forced into posi- -tio'n upon the drill pipe. When the protector has been forced oi! of the expander, the-cone 4 falls to the bottom of the base extension Preferably an opening 24 is provided in the cylindrical base extension for the insertion of the hands of the operator in order to facilitate raising the cone 4 from the base extension at the completion oi' the operation.

While the particular form of the expander herein described is well adapted to carry out the objects or the present invention, it is to be understood that various modifications and changes may be made, and this invention is of the scope set forth in the appended claims.

yI claim:

1. A support for a drill pipe protector which comprises a base including an upper base member, a base extension of hollow cylindrical form and a subbase at the lower end of said extension, a disc resting on the subbase, a centering shaft secured to said disc, a plurality of rigid arms pivoted to the base for limited outward pivoting movement, said! arms extending upwardly and adapted to be pivoted toward the centering shaft. and a protector-contacting pad hinged to each of said arms. t

2. A support for a-drill pipe protector which comprises a base including an upper base membena, base extension of hollow cylindrical form and a subbase at the lower end of said extension, a disc resting on the subbase, acentering shaft secured to said disc, a plurality of rigid arms pivoted to the base for limited outward pivoting movement, said arms extending upwardly and adapted to be pivoted toward the centering shaft, a protector-contacting pad hinged to each of said arms and means included in the hinged connection between the arms and pad for permitting a limited universal movement of said pads relative to said arms. M

JAMES C. BALLAGH.

REFERENCES CITED The following references are of record in the ille of this patent:

UNITED STATES PATENTS 

